SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b876bf1117cffdc6f9172c1fa7cfc587921788cb658a2305f0d6f572e79f365d' 
  AND token = 'R0V05mmqfYmgP17e/GQvLN3p+6Y0tKF3hEWFOjf8H8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}